ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
  • Seismological Society of America  (15)
  • Seismological society of america  (1)
  • Wiley-Blackwell
Sammlung
Erscheinungszeitraum
  • 1
    Publikationsdatum: 2017-04-04
    Beschreibung: On 6 April 2009, 01:32:40 UTC, an Mw 6.3 earthquake occurred in the Abruzzo region (central Italy), close to L’Aquila, a town of 68,500 inhabitants. About 300 people died because of the collapse of many residential and public build¬ings, and damage was widespread in L’Aquila and its neighbor¬ing municipalities. The earthquake occurred at 9.5 km depth along a NW-SW normal fault with SW dip, located below the city of L’Aquila (Istituto Nazionale di Geofisica e Vulcanologia [INGV] 2009a). The maximum observed intensity is IX–X in the MCS scale and the most relevant damages are distributed in the NW-SE direc¬tion, with evident predominance toward the southeast (Istituto Nazionale di Geofisica e Vulcanologia 2009b). This event rep¬resents the third largest earthquake recorded by strong-motion instruments in Italy, after the 1980 Mw 6.9 Irpinia and the 1976 Mw 6.4 Friuli earthquakes (Luzi et al. 2008). The mainshock was followed by seven aftershocks of moment magnitude larger than or equal to 5, the two stron¬gest of which occurred on April 7 (Mw = 5.6) and April 9 (Mw = 5.4). The mainshock and its aftershocks have been recorded by several digital stations of the Italian strong-motion network (Rete Accelerometrica Nazionale, R AN), operated by the Italian Department of Civil Protection (DPC); by the Italian seismometric network (Rete Sismometrica Nazionale, operated by INGV-Centro Nazionale Terremoti (CNT); http://cnt. rm.ingv.it); and by a temporary strong-motion array installed by the INGV Sezione di Milano-Pavia (MI-PV; http://www. mi.ingv.it). A total of 56 three-component strong-motion record¬ings were obtained within 280 km for the mainshock, with 23 being within 100 km of the epicenter. Horizontal peak ground motions in the near-fault region range from 327 to 646 cm/sec2, the latter representing one of the highest values recorded in Italy. This strong-motion data set, consisting of 954 waveforms from Mw 〉 4.0 events, is unique in Italy because it is entirely digital and includes observations from near-fault dis¬tances to some hundred kilometers away. The data set has been integrated in the new Italian strong-motion database ITACA (ITalian ACcelerometric Archive), available at http://itaca. mi.ingv.it. This paper provides an overview of the strong-motion recordings of the mainshock and the two strongest aftershocks with preliminary analyses of different strong-motion param¬eters as a function of distance, azimuth, and site conditions.
    Beschreibung: Published
    Beschreibung: 951-966
    Beschreibung: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): L'Aquila ; strong-motion ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Publikationsdatum: 2017-04-04
    Beschreibung: Abstract We critically analyze the results on seismic intensity attenuation in Italy derived by Albarello and D’Amico (2004) and Gasperini (2001).We demonstrate that, due to the inadequacy of certain underlying assumptions, the empirical relationships determined in those studies did not best reproduce the decay of intensity as the distance from the source increases. We reconsidered some of the relevant concepts and assumptions used in these intensity-attenuation studies (macroseismic epicenter, epicentral intensity, data completeness) to suggest some useful recipes for obtaining unbiased estimates. In particular, we suggest that (1) data for distances from the source at which an intensity below the limit of diffuse perceptibility (≤IV) is expected should be excluded from attenuation computations because such data are clearly incomplete, (2) attenuation equations that include a term proportional to the epicentral intensity I0 with a coefficient different from 1.0 must not be used because they imply a variable offset between I0 and the intensity expected at the epicenter, and (3) epicentral intensities must be recomputed consistently with the attenuation equation because those reported by the Italian catalog do not generally correspond with the intensity predicted at the epicenter by the attenuation relationships so far proposed. Following these suggestions produces a significant reduction in the standard deviation of the model that might lead to a corresponding reduction of the estimates of seismic hazard.
    Beschreibung: Published
    Beschreibung: 682-691
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Macroseismic intensity, Ground motion equation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Publikationsdatum: 2017-04-04
    Beschreibung: Abstract Several different attenuation models have recently been proposed for the Italian region to characterize the decay of macroseismic intensity with the distance from the source. The significant scatter between these relationships and some significant drawbacks that seem to characterize previous approaches (described in a companion article by Pasolini et al., 2008) suggest that the problem needs to be reconsidered. As a first step toward more detailed analyses in the future, this study aimed at developing an isotropic attenuation relationship for the Italian area. Because this attenuation relationship has to be used primarily in probabilistic seismic hazard assessment, major attention was given to evaluating the attenuation relationship in its complete probabilistic form. Another important aspect of this study was the preliminary evaluation of the intrinsic (i.e., independent of the specific attenuation relationship to be used) scattering of data, which represents the lowest threshold for the residual variance that cannot be explained by the attenuation relationship. Furthermore, the peculiar formal features of intensity data and relevant uncertainties were considered carefully. To reduce possible biases, the completeness of the available database was checked and a suitable data selection procedure was applied. Since epicentral intensity cannot be defined unambiguously from the experimental point of view, the attenuation relationship was scaled with a new variable that is more representative of the earthquake dimension. Several criteria were considered when evaluating competing attenuation formulas (explained variance, Bayesian information criteria, Akaike information criteria, etc.). Statistical uncertainty about empirical parameters was evaluated by using standard approaches and bootstrap simulations. The performance of the selected relationship with respect to a control sample was analyzed by using a distribution-free approach. The resulting equation for the expected intensity I at a site located at epicentral distance R is I IE 0:0086 0:0005 D h 1:037 0:027 ln D ln h ; where D R2 p h2, h 3:91 0:27 km, and IE is the average expected intensity at the epicenter for a given earthquake that can be computed from the intensity data (when available) or by using empirical relationships with the moment magnitude Mw or the epicentral intensity I0 reported by the Italian seismic catalog IE 5:862 0:301 2:460 0:055 Mw; IE 0:893 0:254 1:118 0:033 I0: Comparison of the model standard deviation (S.D.) (0.69 intensity degrees) with the intrinsic one (0.62) indicates that this attenuation equation is not far from being optimal.
    Beschreibung: Published
    Beschreibung: 692-708
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Macroseismic intensity, Ground motion prediction equation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Publikationsdatum: 2021-06-25
    Beschreibung: We provide a complete description of the characteristics of excitation and attenuation of the ground motion in the Lake Van region (eastern Turkey) using a data set that includes three-component seismograms from the 23 October 2011 Mw 7.1 Van earthquake, as well as its aftershocks. Regional attenuation and source scaling are parameterized to describe the observed ground motions as a function of distance, frequency, and magnitude. Peak ground velocities are measured in selected narrow frequency bands from 0.25 to 12.5 Hz; observed peaks are regressed to define a piecewise linear regional attenu- ation function, a set of excitation terms, and a set of site response terms. Results are modeled through random vibration theory (see Cartwright and Longuet-Higgins, 1956). In the log–log space, the regional crustal attenuation is modeled with a bilinear geo- metrical spreading g r characterized by a crossover distance at 40 km: g r ∝ r^−1 fits our results at short distances (r 〈 40 km), whereas g r ∝ r^−0.3 is better at larger distances (40 〈 r 〈 200 km). A frequency-dependent quality factor, Q f =100( f/fref)^ 0:43 (in which fref 1.0 Hz), is coupled to the geometrical spreading. Because of the inherent trade-off of the excitation/attenuation parameters (Δσ and κ), their specific values strongly depend on the choice made for the stress drop of the smaller earthquakes. After choosing a Brune stress drop ΔσBrune 4 MPa at Mw 3:5, we were able to define (1) an effective high frequency, distance- and mag- nitude-independent roll-off spectral parameter, κeff = 0:03 s and (2) a size-dependent stress-drop parameter, which increases with moment magnitude, from ΔσBrune 4 MPa at Mw 3.5 to ΔσBrune 20 MPa at Mw 7.1. The set of parameters mentioned here may be used in order to predict the earthquake-induced ground motions expected from future earthquakes in the region surrounding Lake Van.
    Beschreibung: Published
    Beschreibung: 4T. Fisica dei terremoti e scenari cosismici
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Earthquake-induced ground motion, Lake Van, Crustal attenuation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Publikationsdatum: 2017-04-04
    Beschreibung: We evaluate the goodness of fit of attenuation relations commonly used for the Italian national territory (Sabetta and Pugliese, 1996) by using the maximum likelihood approaches of Spudich et al. (1999) and Scherbaum et al. (2004). According to the classification scheme proposed by Scherbaum et al. (2004), the Sabetta and Pugliese (1996) relationships show consistent discrepancies between the predicted and the observed peak ground acceleration (PGA) at rock sites in the Umbria- Marche region, central Italy; however, at soft sites the agreement between observations and prediction is satisfactory. The bias of the residuals, computed with the Sabetta and Pugliese (1996) models for PGA, peak ground velocity, (PGV) and pseudovelocity response spectrum (PSV) (for Ml 4–6 and epicentral distances up to 100 km) is negative. This means that on the average, the predictions overestimate the observations, but the overestimation decreases with increasing magnitude. Then, we present regional predictive relations (UMA05) for maximum horizontal PGA, PGV, and 5%-damped PSV, derived from the strong-motion data recorded in the Umbria-Marche area and classified as to four site categories. The UMA05 attenuation relationships for rock sites are log10 (PGA) 2.487 0.534Ml 1.280 log10 (R2 3.942)0.5 0.268 log10 (PGV) 1.803 0.687Ml 1.150 log10 (R2 2.742)0.5 0.300 and log10 (PGA) 2.500 0.544Ml 1.284 log10 Rh 0.292 log10 (PGV) 1.752 0.685Ml 1.167 log10 Rh 0.297, where PGA is measured in fraction of g and PGV in centimeters per second, Ml is the local magnitude in the range 4–6, R is the epicentral distance in the range 1–100 km, and Rh is the hypocentral distance in kilometers. We used the random effect model (Brillinger and Priesler, 1985; Abrahamson and Youngs, 1992; Joyner and Boore, 1993; Joyner and Boore, 1994) to estimate the component of variance related to the earthquake-to-earthquake, station-to-station, and record-to-record variability, and to quantify the benefit of introducing a site classification in the attenuation model to reduce the variance. The introduction of the site classification in the attenuation model allows a reduction of the station-to-station component of variability (from 0.19 to 0.14 for PGA, and from 0.21 to 0.18 for PGV). We also found that the recordto- record component represents the largest contribution to the model uncertainty.
    Beschreibung: Published
    Beschreibung: 984-1002
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Ground-Motion ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Publikationsdatum: 2017-04-04
    Beschreibung: The Italian strong-motion database contains 2182 three component waveforms generated by 1004 earthquakes with a maximum magnitude of 6.9 (1980 Irpinia earthquake) covering the period range from 1972 to 2004. The database is devoted to serving the seismological and engineering communities. The database can be accessed on-line at the site http://itaca.mi.ingv.it, where a wide range of search tools enables the user to interactively search events, recording stations and retrieve waveforms with particular characteristics, whose parameters can be specified, as needed, through a graphical user interface. A range of display options allows users to view data in different contexts, extract and download time series and spectral data. The database was created during a joint project between Istituto Nazionale di Geofisica e Vulcanologia (INGV, Italian institute for geophysics and vulcanology) and Dipartimento della Protezione Civile (DPC, Italian civil protection). The aim of the project was the collection, homogenization and distribution of data acquired over the time period 1972-2004 in Italy by different Italian institutions, namely Ente Nazionale per l’Energia Elettrica (ENEL, Italian electricity company), Ente per le Nuove tecnologie, l’Energia e l’Ambiente (ENEA, Italian energy and environment organization) and DPC. The project had multiple purposes, such as permanent strong motion monitoring and temporary monitoring during seismic sequences or before permanent installation. This database brings up to date the ENEA strong motion data collection which ended in 1993 and the European database where the most recent Italian data pertain to the Umbria-Marche sequence of 1997-1998 (Ambraseys at al., 2002). In addition effort was spent reviewing strong motion metadata and data processing to increase data quality and reliability. This article describes the steps that led to the completion of the project and provides an overview of the search capabilities available at the database interface website.
    Beschreibung: Published
    Beschreibung: 716-722
    Beschreibung: 5.2. TTC - Banche dati di sismologia strumentale
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): strong-ground motion ; database ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Publikationsdatum: 2017-04-04
    Beschreibung: Abstract We simulated strong-motion records from the Umbria–Marche, central Italy, earthquake (Mw 6) of September 1997 using a frequency-dependent S-wave radiation function. We compared the observed acceleration spectra, from strongmotion instruments located in the near field and at regional distances, with those simulated using the stochastic modeling technique of Beresnev and Atkinson (1997, 1998), and modified to account for a frequency-dependent radiation pattern correction. By using the frequency-dependent radiation function previously obtained by Castro et al. (2006), we reduced the overall fitting error of the acceleration spectra by about 9%. In general, we observed that the frequency-dependent radiation pattern correction has a small effect on the spectral amplitudes compared with site effects, which is an important factor controlling the strong-motion records generated by the 1997 Umbria–Marche earthquake. In addition, we modeled the observed ground-motion records using the dynamic corner frequency model of Motazedian and Atkinson (2005) to reproduce the directivity effects, reducing the average error of the spectral amplitudes by 24%. We concluded that although the frequencydependent radiation pattern correction affects the frequency content of the spectral amplitudes simulated, site and directivity effects are more relevant.
    Beschreibung: Published
    Beschreibung: 662–670
    Beschreibung: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): strong motion ; simulation ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Publikationsdatum: 2017-04-04
    Beschreibung: Abstract The source parameters of 523 aftershocks (0.5 ML 5.9) of the 1999 Kocaeli earthquake are determined by performing a two-step spectral fitting procedure. The source spectrum, corrected for both site and propagation effects, is described in terms of a standard x-square model multiplied by an exponential term of frequency. The latter term is introduced to estimate the high-frequency (f 12 Hz) fall-off of the acceleration source spectra by computing the j parameter. The seismic moments obtained range between 1.05 1014 and 2.41 1017 N m, whereas the Brune stress drops are between 0.002 and 40 MPa. The j value varies between 0.00 and 0.08 sec, indicating a decay of the acceleration level at the higher frequency part of the spectrum greater than that assumed by the x 2 model. Both the stress drop and the j parameter show the tendency of increasing with aftershock magnitude. No evidence of self-similarity breakdown is observed between the source radius and M0. Finally, both the seismic moment and the moment magnitude are compared with the local magnitude to derive new moment–magnitude relationships for the area.
    Beschreibung: Published
    Beschreibung: 655-660
    Beschreibung: 3.3. Geodinamica e struttura dell'interno della Terra
    Beschreibung: JCR Journal
    Beschreibung: partially_open
    Schlagwort(e): Source parameters ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Publikationsdatum: 2017-04-04
    Beschreibung: Seismograms from 55 intermediate-depth Vrancea earthquakes (M 4:0– 7:1) recorded at 43 stations of an accelerometric network in Romania are used to derive source spectra and site amplification functions from S waves in the frequency range 0.5–20 Hz with the generalized inversion technique (GIT) (Castro et al., 1990). Attenuation is taken into account using the nonparametric attenuation functions derived by Oth et al. (2008) from the same dataset, and the attenuation-corrected data are then split into source and site contributions. The source spectra follow the ω 2 model (Brune, 1970, 1971) with high corner frequencies and a related Brune stress drop of the order of 100 MPa. The site amplification functions are separately determined for both horizontal and vertical components. Contrary to widespread expectation, the vertical component shows significant amplification effects at high frequencies. The H=Z ratios determined from the GIT results compare well with H=V ratios computed directly from the S-wave window of the accelerograms (Lermo and Chávez-García, 1993). The basic assumption for the determination of site effects from H=V ratios is that the vertical component is not or only little affected by site effects. For Vrancea earthquakes, this assumption is incorrect; consequently, site effects should not be estimated from H=V ratios. The reason for this peculiar fact is the geometry of intermediate-depth seismicity that leads to almost vertical ray paths beneath the stations.
    Beschreibung: Published
    Beschreibung: 235-254
    Beschreibung: 4.1. Metodologie sismologiche per l'ingegneria sismica
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): source spectra ; Vrancea region ; site effects ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Publikationsdatum: 2017-04-04
    Beschreibung: The goals of this work are to review the Northern-Italy ground-motion prediction equations (GMPEs) for amplitude parameters and to propose new GMPEs for frequency content and duration parameters. Approximately 10,000 weak and strong waveforms have been collected merging information from different neighboring regional seismic networks operating in the last 30 yr throughout Northern Italy. New ground-motion models, calibrated for epicentral distances ≤100 km and for both local (ML) and moment magnitude (Mw), have been developed starting from a high quality dataset (624 waveforms) that consists of 82 selected earthquakes with ML and Mw up to 6.3 and 6.5, respectively. The vertical component and the maximum of the two horizontal components of motion have been considered, for both acceleration (peak ground horizontal acceleration [PGHA] and peak ground vertical acceleration [PGVA]) and velocity (peak ground horizontal velocity [PGHV] and peak ground vertical velocity [PGVV]) data. In order to make comparisons with the most commonly used prediction equations for the Italian territory (Sabetta and Pugliese, 1996 [hereafter, SP96] and Ambraseys et al. 2005a,b [hereafter, AM05]) the coefficients for acceleration response spectra (spectral horizontal acceleration [SHA] and spectral vertical acceleration [SVA]) and for pseudovelocity response spectra (pseudospectral horizontal velocity [PSHV] and pseudospectral vertical velocity [PSVV]) have been calculated for 12 periods ranging between 0.04 and 2 sec and for 14 periods ranging between 0.04 and 4 sec, respectively. Finally, empirical relations for Arias intensities (IA), Housner intensities (IH), and strong motion duration (DV) have also been calibrated. The site classification based on Eurocode (hereafter, EC8) classes has been used (ENV, 1998, 2002). The coefficients of the models have been determined using functional forms with an independent magnitude decay rate and applying the random effects model (Abrahamson and Youngs, 1992; Joyner and Boore, 1993) that allow the determination of the interevent, interstation, and record-to-record components of variance. The goodness of fit between observed and predicted values has been evaluated using the maximum likelihood approach as in Spudich et al. (1999). Comparing the proposed GMPEs with SP96 and AM05, it is possible to observe a faster decay of predicted ground motion, in particular for distances greater than 25 km and magnitudes higher than 5.0. The result is an improvement in fit of about one order of size for magnitudes spanning from 3.5 to 4.5.
    Beschreibung: Published
    Beschreibung: 1319-1342
    Beschreibung: 1.1. TTC - Monitoraggio sismico del territorio nazionale
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): ground motion prediction equations ; north italy ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.06. Seismology::04.06.04. Ground motion ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...